"The need to represent" seems to be operative, here, so I looked up
the term "represent" at Urban Dictionary dot COM and found several
definitions, including:
3.) "To annoy others with your presence. An activity often carried out by 'playaz'" ['players', for you white folk, meaning : A
male who is skilled at manipulating ("playing") others...A certain
class of low-rent, slack-jawed f#ckups has decided that backstabbing and
misogyny are totally radical... (also Urban Dictionary)]..
6.) A phrase showing acknowledgement to one's background, home, social group, or original place of residence. Also similar to giving a Shout Out to one's homeboys. [sic]
So, I'm guessing the the "phrase" Harley-Davidson is you your way of shouting out to your homies,
those others who have set themselves apart from the general
motorcycling community through conspicuous consumption of high-end
boutique goods.
I'm just a pretend psychiatrist, not a sociologist, so I could be wrong.